Field of the Invention
The application provides intraluminal prosthesis, methods for the manufacture of intraluminal endoprostheses and mandrels for the manufacture of such endoprostheses.
Description of the Related Technology
Endoprostheses are a commonly used way of dealing with diseases in interventional medicine and surgery. Mesh-based endoprostheses such as stents, stent grafts, heart valve frames, etc. are of particular importance in cardiovascular applications. Also other fields of medicine make use of such endoprostheses, e.g. pulmonary tract stents, oesophagus stents, etc.
Intraluminal endoprostheses such as stents are typically designed such that they are deployable by catheter or similar stent delivery system, as it is desirable for stent placement procedures to be minimally invasive. Some stents are self-expandable, whereas other stents are inflated via a balloon inside the stent in order to force the stent to open.
Currently, the majority of stents have a cylindrical outer shape, regardless of the anatomy of the lumen in which the stents are to be deployed. Although stents typically are flexible, insertion of a stent which is not optimized to fit the exact patient's anatomy often leads to suboptimal intervention results including localized turbulence in the blood, unnatural stresses on the vessel wall, vessel injury, endoprosthesis breaking, endoprosthesis migration, etc.
U.S. Pat. No. 7,722,663 describes a method for manufacturing a custom, personalized endoprosthesis using a mandrel which is adapted to the actual patient's anatomy. In this method, a V-shape undulated wire, typically in a shape memory or superelastic alloy, is draped around the mandrel, followed by a heat treatment to set the wire onto the mandrel. The wire is then unwrapped from the mandrel in a helical fashion. A problem with this method is that it only allows for the use of shape memory alloy wires or super-elastic wire without links between two adjacent rows of helical wires. Indeed, unwrapping of the wire from the mandrel is only possible when the adjacent rows are not interconnected. Additionally, a heat treatment process on the super-elastic wire is required to restore the desired shape after it has been removed from the mandrel.
A solution to these problems is presented in US patent application 2005/096729, which discloses a method for the manufacture of a stent, wherein the stent is separated from the mandrel by dissolving the mandrel. However, this method involves the use of hazardous acids, and limits the amount of materials which can be used to manufacture the stents.
Accordingly, there is a need for improved methods for the production of endoprostheses such as stents, which at least partially mitigate the problems stated above.